text: 'use strict';
  
  // From https://en.wikipedia.org/wiki/Discriminant :
  //
  //   Delta = b^2 - 4ac.
  var quadraticDiscriminantFormula = (function() {
    var a = ComplexFormula.select(-1);
    var b = ComplexFormula.select(-2);
    var c = ComplexFormula.select(-3);
    return b.pow(2).minus(a.times(c, 4));
  })();
  
  // From https://en.wikipedia.org/wiki/Quadratic_formula :
  //
  //   x = (-b + sqrt(Delta)) / 2a,
  //
  // where both complex square roots are taken.
  function newQuadraticFormula() {
    var a = ComplexFormula.select(-1);
    var b = ComplexFormula.select(-2);
    var c = ComplexFormula.select(-3);
    var disc = quadraticDiscriminantFormula;
    return b.neg().plusAll(disc.root(2)).divAll(a.times(2));
  };
  